That's like saving nuts, bolts and washers if they are in good shape ( I do it!) My elder son protests about the weight of excess stuff- until we need to put something together or do a quick repair. Then the oddments of rope and fittings stashed away will save your day - if you are lucky!
One trick might be of use to someone is making fenders out of rope. Based on macrame.
Take a long piece of thick rope fold in half. Now tie the two ends together in a reef knot. The size of the loop above the reef knot makes the attachment loop. Now tie another reef knot against the first and another and another. You make a thick plat of rope which can work well as a fender. Lash the ends together with whipping cord to finish it and make another attachment if needed. You can make a fender mat as wide as you want by starting with 2 folded pieces of rope or any number of pieces. Each reef knot alternates with itself or neighbouring rope.
I bring my boat home every winter and remove all the excess junk. Leaving just what has proven to be needed in the pervious season. good luck olewill